Room-temperature ionic liquids have shown great potential as media for reactions and separations. Information on how solutes interact with these solvents is crucial in assessing their usefulness. Here, the quantitative structure-property relationship (QSPR) method is used to correlate values of infinite-dilution activity coefficients for 38 solutes in three ionic liquids. Constant-temperature and temperature-dependent correlations are created with correlation coefficients ranging from R-2 = 0.90 to R-2 = 0.99. In addition, correlation parameters are analyzed to understand the interactions that affect infinite-dilution activity coefficients.